1. Field of the Invention
The present invention relates to a touch display technology, and more particular to a self-capacitive touch panel structure, an in-cell touch panel, and a liquid crystal display.
2. Description of Related Art
A touch panel as an input medium is the most simple and convenient human-computer interaction method. Therefore, the touch panel is more widely applied to a variety of electronic products. Based on different operation principles and interfaces for transmitting information, touch panel products can divide into four types: an infrared touch panel, a capacitive touch panel, a resistive touch panel and a surface acoustic wave touch panel. Wherein, the capacitive touch panel becomes the mainstream of touch panel technology because a long life, high transmittance, capable of supporting multiple touches, etc. The capacitive touch panel includes a surface capacitive type and a projected capacitive type. The projected capacitive type can be divided into a self-capacitive type and a mutual capacitive type. The self-capacitive touch panel structure, due to higher touch sensing accuracy and signal to noise ratio are favored by major panel manufacturers.
Currently, the self-capacitive touch panel structure utilizes a self-capacitance principle to detect a touch location of a finger. Specifically, multiple self-capacitance electrodes which are disposed at a same layer and isolated with each other are disposed in the touch panel structure. When a human body does not contact with the touch panel, a capacitance applied on each self-capacitance electrode is a fixed value. When a human body contact with the touch panel, a capacitance applied on a self-capacitance electrode which is corresponding to a touch location is the fixed value adding a human capacitance. A touch detection chip can determine the touch location in a touch time interval through detecting a capacitance change of each self-capacitance electrode.
FIG. 1 is a schematic diagram of a self-capacitive touch panel structure according to the conventional art. As shown in FIG. 1, the self-capacitive touch panel includes M rows and columns self-capacitance electrodes Rxy (R11˜RM1˜R1N˜RMN), and a touch detection chip 1. Each self-capacitance electrode Rxy utilizes a single connection line Lyx to connect with the touch detection chip 1. Specifically, the self-capacitance electrodes Rxy and the connection lines Lyx are disposed at different layers, and each self-capacitance electrode Rxy utilizes a via hole 2 to electrically connect with a corresponding connection line Lyx. That is, each column of the self-capacitance electrodes R1y˜RMy is sequentially connected with a group of the connection lines Ly1˜LyM in order.
As sown in FIG. 1, from a bottom side to a top side, the first column of the self-capacitance electrodes R11˜RM1 are respectively corresponded to a group of the connection lines L11˜L1M which are from a left side to a right side. Each connection line L1x is connected with a corresponding self-capacitance electrode Rx1, and each connection line L1x is disconnected with other self-capacitance electrodes in order to realize an independent control of each self-capacitance electrode Rx1. That is, each self-capacitance electrode Rx1 connected with the connection line L1x is not connected with previous self-capacitance electrodes R11˜R(x−1)1. After the connection line L1x is connected with the corresponding self-capacitance Rx1, the connection line L1x does not connect with following self-capacitance electrodes R(x+1)1˜RM1.
Specifically, the first self-capacitance electrode R11 of the self-capacitance electrodes R11˜RM1 is connected with the touch detection chip 1 through the first connection line L11 of the group of the connection lines L11˜L1M, the second self-capacitance electrode R21 of the self-capacitance electrodes R11˜RM1 is connected with the touch detection chip 1 through the second connection line L12 of the group of the connection lines L11˜L1M, and so on, the Mth self-capacitance electrode RM1 is connected with the touch detection chip 1 through the Mth connection line L1M. Wherein, in the above symbols, x=1, 2, 3 . . . , M; y=1, 2, 3 . . . , N.
In the structure of the self-capacitive touch panel described above, because each column of the self-capacitance electrodes R1y˜RMy is sequentially connected with a group of the connection lines Ly1˜LyM in order. For the same column of the self-capacitance electrodes R1y˜RMy, lengths of the group of the connection lines Ly1˜LyM corresponding to the column are increased gradually. The self-capacitance electrode RMy farther away from the touch detection chip 1, the corresponding connection line LyM is longer. Finally, for the display situation of entire structure of the touch panel, a slash display uneven phenomenon (slash mura) will generate at an end of the group of the connection lines Ly1˜LyM, as shown at an area “A” in FIG. 1 so as to affect the display quality.